The present invention relates to a break-away bracket, e.g., a break-away steering column bracket. The break-away bracket includes a bracket shell having a central channel and sidewalls having outwardly extending flanges, a clip extending over at least a portion of each flange, and a plurality of exterior reinforcing plastic ribs attached to the exterior of the bracket shell. Each clip and flange arrangement of the break-away bracket has at least one shearable pin, e.g., a shearable plastic pin, extending therethrough.
A break-away bracket is typically used in those applications where it is desired that the bracket (and the structure that is held within the bracket) separate or break-away from the support structure to which the bracket is fastened, under certain conditions. For example, within the passenger compartment of an automobile, the steering wheel is attached to a steering shaft, which is supported within a steering column. The steering column is typically attached to a cross-car support beam by means of a bracket. If the automobile is involved in a front-end collision, it is desirable that the bracket and steering column separate or break-away from the cross-car beam and move forward, for purposes of minimizing injury to the driver resulting from impact with the steering wheel.
In, for example, the automotive industry it is desirable to minimize the weight of the vehicle in an effort towards maximizing fuel efficiency. The total weight of a vehicle can be reduced by reducing the weight of its components. However, it is generally required that the strength and rigidity of a component not be compromised as the weight of the component is reduced.
It is known that a component having a unitary molded plastic structure, formed for example by injection molding, can have reduced weight relative to an equivalent component fabricated from metal. However, unitary molded plastic parts typically have lower strength and rigidity compared to equivalent parts fabricated from metal.
It would be desirable to develop a break-away bracket that has reduced weight. It is also desirable that the break-away bracket have, in addition to reduced weight, good strength and rigidity.
U.S. Pat. No. 5,190,803 describes a lightweight structural component having high strength and rigidity, which includes a bowl-shaped shell, e.g., fabricated from metal, and injected-on plastic reinforcing ribs located within the interior of the shell. The plastic reinforcing ribs are described in the ""803 patent as being connected to the shell at discrete connecting points by means of perforations in the shell through which the plastic extends and in which the edges of the perforations are embedded.
U.S. Pat. No. 6,027,088 describes a steering column support bracket, which includes a molded plastic frame having a pair of laterally spaced apart side braces, a front brace interconnecting the front ends of the side braces, and an intermediate brace located between the front and rear ends of the side braces. The steering column support bracket of the ""088 patent also includes an X-shaped truss having legs extending diagonally between the side braces, and between the intermediate brace and the rear ends of the side braces.
U.S. Pat. No. 5,979,860 describes a steering column support apparatus having two capsules on either side of the steering column. The capsules of the ""860 patent are described as including severable plastic ribs, which allow the steering column to collapse forwardly in a crash situation.
U.S. Pat. No. 5,944,348 describes a collapsible steering column support structure. The steering column support structure of the ""348 patent includes a bracket having release capsules (e.g., fabricated from nylon) which frictionally or slidably engage the steering column to permit stroke of the steering column in the event of a frontal impact of sufficient magnitude.
In accordance with the present invention, there is provided a break-way bracket comprising:
(a) a bracket shell having interior surfaces, exterior surfaces, and two sidewalls, each sidewall having a laterally outwardly extending flange, the interior surfaces of said bracket shell defining a central channel, each flange having a plurality of perforations and a rear edge having an open ended slot;
(b) a clip extending over at least a portion of each flange, each clip having an upper plate and a lower plate, each of said upper and lower plates having a plurality of perforations, at least a portion of each flange being interposed between the upper and lower plates of each clip, and at least some of the perforations of the upper and lower plates of each clip and the perforations of the interposed portion of each flange being aligned and together defining at least one shearing pin passage for each clip and flange, the upper and lower plates of each clip each having an aperture aligned with said open ended slot of each flange which together define a fastener hole for each clip and flange;
(c) at least one shearable pin, e.g., a shearable plastic pin, extending through at least one of said shearing pin passages of each clip and flange; and
(d) a plurality of exterior reinforcing ribs of plastic material in abutting relationship with and fixedly attached to at least a portion of the exterior surfaces of said bracket shell and at least a portion of at least one of said clips.
In accordance with the present invention, there is further provided a break-away bracket as described above wherein,
said bracket shell has a plurality of perforations;
said exterior reinforcing ribs are formed by molding, e.g., injection molding, of plastic material onto the exterior surfaces of said bracket shell and each of said clips, a portion of the plastic material of said exterior reinforcing ribs extends through at least some of said perforations of said shell, the edges of said perforations of said bracket shell being embedded in the plastic material extending therethrough, thereby fixedly attaching said exterior reinforcing ribs to the exterior of said bracket shell; and
a portion of the plastic material of said exterior reinforcing ribs extends through said shearing pin passages to form shearable plastic pins therein, the edges of said shearing pin passages being embedded in the plastic material extending therethrough, thereby anchoring said shearable plastic pins within said shearing pin passages and fixedly attaching said exterior reinforcing ribs to each clip and flange.
The features that characterize the present invention are pointed out with particularity in the claims, which are annexed to and form a part of this disclosure. These and other features of the invention, its operating advantages and the specific objects obtained by its use will be more fully understood from the following detailed description and accompanying drawings in which preferred embodiments of the invention are illustrated and described.
Unless otherwise indicated, all numbers or expressions, such as those expressing structural dimensions, quantities of ingredients, etc. used in the specification and claims are understood as modified in all instances by the term xe2x80x9cabout.xe2x80x9d